1. Field
The invention pertains to guide devices for hydraulic hoses employed on snow grooming vehicles.
2. State of the Art
Inserts called grommets or eyelets are commonly used in perforations through metallic bulkhead walls to protect insulated electric wires from laceration. Power cords for electric fan motors, for example, pass through the fan housings via such grommet shielded holes. The grommets are often of elastic material, and are sized to immobilize the wires by snugly gripping the exterior insulation. Metallic or plastic eyelets strengthen and protect shoe lace holes, to cite another example. Little if any relative motion occurs between tied laces and eyelets when the shoes are worn.
For snow grooming vehicles, on the other hand, guide devices must often permit back and forth motion of hydraulic hoses. This permits hydraulic actuators and the like to be mounted upon articulated moving components of the vehicle and attached equipment. Often, for example, hydraulic rams for adjusting the attitude of a snow plow blade are mounted upon a blade lift frame. The lift frame in turn is continually lifted and lowered with respect to the vehicle, causing the ram hydraulic supply hoses to slide reciprocally in guide rings. This motion causes the rubberoid sheathed hoses to be abraded by the inside of the rings, necessitating all too frequent hose replacement. The guiding forces between the ring and the serpentinely mounted hoses are often considerable, because of the high fluid pressure.
Steel rings of circular cross sections are commonly employed, providing a smoothly curving surface to reduce hose abrasion. However, snow and ice tend to adhere to the steel rings, obstructing free motion of the hoses in the rings. Rust adds to the abrasiveness of the ring, by roughening the surface and destroying the smooth, hose contacting contour. This is aggravated by granular imperfections found in steel, especially in economically acceptable formulations. To reduce ring oxidation is quite expensive. Non-oxidizing metal plating upon the rings lacks sufficient durability. Further, replating deteriorated surface rings is inconvenient and expensive, requiring removal and reinstallation after plating. Also, each plate material has its own problems. Chrome, for example tends to adhere strongly to snow. Clearly, an improved method of retaining and guiding the reciprocating hoses is needed to reduce hose abrasive damage to acceptable levels.